Powder Forecast – Tuesday, April 14th, 2026
Ted Schlaepfer CCM —- Mammoth Mountain WeatherGuy
Snowfall forecasts are valid at the Sesame snow course (Main Lodge) for the prior 24 hours as reported in the 6-7 AM morning snow report.
**Snowfall forecast confidence ranges from very low (1) to very high (5)
Wed 4/15 = 0”
Thu 4/16 = 0”
Fri 4/17 = 0”
Sat 4/18 = 0”
Sun 4/19 = 0”
Mon 4/20 = 0 – 2″
Tue 4/21 = 3 – 6″
Wed – Fri 4/22 – 4/24 = 1 – 3”
April Snowfall = 32”
April Forecast = 25 – 45″
Detailed 4-day Snowfall Forecast:
Wed 4/15 through Sat 4/18 – No snowfall expected all days except for a chance for flurries Thursday morning.
Forecast Summary:
Short Term (Days 1 – 4):
The current infrared satellite image (below) this afternoon shows a weak area of high pressure has built over the state, with the next upstream weather system currently positioned off the Pacific Northwest coast. High pressure should hold through tomorrow before getting displaced eastward on Thursday.
That is because the weather system currently off the Pacific Northwest coast will move southward through eastern California and Nevada on Thursday as an inside slider-type trough. Any precipitation will stay north of Mammoth, with the main effect being breezy winds and colder winter-like temperatures. Would not be surprised to see some wind buff up Top both Wednesday and Thursday.
High pressure then rebuilds into the state Friday and Saturday, bringing fair, dry weather and warmer temperatures, with spring conditions in the lower/middle parts of the mountain by Saturday.
Long Range (Days 5+):
The longer-range guidance is still looking pretty good for April, although nothing is guaranteed this time of year. The models are favoring another storm for late next weekend and into next week, and then keep at least a weak longwave mostly in place for the rest of the month.
The guidance is mostly in agreement that another late-season upper-level trough will move southward into CA either late next weekend or early over the following week, per the ECM model (image below), which is well supported by the ECM EPS (two images below).
It appears to be deep enough for a surface low to develop, and it has decent southwest flow into the Sierra, associated with a moderately strong jet stream. The only big difference is that the GFS is slower than the ECM, with landfall almost a day later and weaker by the time it gets to Mammoth.
The pattern is likely being driven by influences from the tropics, as there is an ongoing MJO event of decent amplitude, with the signal currently in phase 7 (image below). The models (ECM below) show the anomalous signal moving through phase 8 and into phase 1 by the end of week 3. 
Looking at the MJO precipitation anomaly chart (image below,), where the black line/arrow shows the ECM model forecast (it is like Ms Pacman, where you go out one side and emerge on the other), faster eastward movement into phase 1 during week 3 would favor better precipitation chances of more significant precipitation versus phase 8, which shows normal precipitation. Normal precipitation this time of year for Mammoth would be around 0.50″ for that week.
The QPF from the ECM model is currently the largest, at about 0.75″ liquid (image below), whereas the GFS washes out the front in the Central Sierra and only has about 0.35″ for Mammoth (two images below). The ECM EPS is closer to the deterministic run at about 0.65″ (three images below).
The forecast leans toward the ECM EPS, with about 6-9″ of snowfall and enough for powder conditions, backed by MJO forcing; best chance on Tuesday. However, Monday could be a story, and the Top might not open until Wednesday.
High pressure returns by the end of the week, bringing fair, dry weather, with spring likely returning to most of the mountain. The ECM EPS 5-day 500-mb height forecast for the last part of April shows a flat ridge over CA. That would mean continued dry weather and seasonable temperatures or spring conditions. The ECM EPS forecast for May (two images below) favors a dry month; next week might be the last call for powder conditions this season. WG
